Regulator.



J. C. BARRY.

REGULATOR.

APPLIOATION FILED SEPT. 13, 1907.

1,003,416. I Patented Sept. 19, 1911.

John Cfiarry UNITED STATES PATENT OFFICE.

JOHN G. BARRY, OF SCHENECIADY, NEW YORK ASSIGNOR TO GENERAL ELECTRICCOMPANY, A CORPORATION OF NEW YORK.

REGULATOR.

Specification of Letters Patent.

Patented Sept. 19, 1911.

To all whom it may concern:

ing the amount of current flowing in each Be it known that I, JOHN C.BARRY, a coil. The coils may be of the same size, and

citizen of the United States, residing at Schenectady, county ofSchenectady, State 5 of New York, have invented certain new and usefulImprovements in Regulators, of which the following is a specification.

My invention relates to dynamo electric machines, such. as boosters, inwhich it is necessary to vary both the direction and amount of currentsupplied by the machine,

' and more particularly to boosters connected in series with storage orsecondary batteries to control the output of the battery. Both thedirection and the amount of current delivered by dynamo electricmachines, particularly boosters connected in series with secondarybatteries, have been controlled by having one field coil for producing aconstant magneto-motiveforce in one direction in the field and varyingor overcoming the effect of the field coil by an opposing coil regulatedby some suitable device such as a rheostat. In order to change thedirection of the current delivered by the machine, the opposing coilmust be more powerful than the field coil and requires considerablecurrent, so that the entire construction is expensive and inefficient. Asingle'ficld coil has also been used arranged so that. a varying amountof current can be sent through it in either direction. This arrangementrequires a reversing switch or equivalent device and complicatedmechanism for controlling the current in either direction.

The object of my invention is to provide a simple and etlicientregulator, which enables both the direction and amount of current from adynamo electric machine to be varied, which will produce a maximumregulating effect with a fixed amount of material and apparatus, whichwill respond quickly to 'aryiiig demands on the machine,

and which is in general an improvement on regulating devices, as is morefully pointed out in the accompanying specification.

In carrying out my invention, a dynamo electric machine is provided withmeans, such as differential wound field coils for producing opposingmagneto-motive forces in the field of the machine together with aregulating or controlling device for simultaneously varying themagneto-motive forces, preferably by simultaneously varywhen one isexerting its maximum effect the other is practically cut out of circuit,so tnat by my invention a maximum range of magneto-motive forces can beimpressed on the field with a minimum amount of winding 011 the fieldand a small current which may be easily controlled. In the preferredarrangement, a resistance is connected in series with each coil, and asone resistance is decreased the other is correspondingly increased,preferably by some suitable automatic device. IVhen my intention is usedto control a booster in series with a secondary battery, thedifferential coils vare preferably connected in shunt with the batteryand booster,.and the current in one coil is increased while that in theother coil is simultaneously decreased by a device responsive to currentin the circuit supplied by the battery.

My invention will best be understood in' ranged in series and connectedacross the circuit and in parallel with the generator 1 for the purposeof equalizing the load on the generator. It is necessary that thebooster be so controlled that when the load on the consumption circuit.is large. the booster will enable the battery to take its share of theload and discharge into the circuit, while when the load on the circuitis small, the booster will enable the generator 1 to charge the storagebattery.

In accordance with my invention, both the direction and'amount ofcurrent delivered by the booster is varied by means, consisting ofdifferentially wound field coils (3 and T, for generating opposingmagneto-motive forces which can be simultaneously varied to control theoutput of the booster. The amount of magneto-motive force in either.

direction generated by the differential coils 6 and 7 is regulated bydecreasing the amount of current flowing through one coil andsimultaneously increasing the amount of current flowing through theother coil. This result may be attained in any suitable manner, but inthe preferred arrangement, as shown in the drawing, both coils areconnected to the lead 2, and also to each other through a resistance 8divided into sections each connected to a field contact 9, the wholeforming the resistance unit of a rheostat, of which the other member isa movable contact arm 10 moving over and engaging the fixed contacts 9,and thereby varying the amount of resistance between the end of thecontact arm 10 and one or the other of the coils 6 and 7. The contactarm 10 is connected through a lead 11 to the other lead 3 of theconsumption circuit, so that both coils 6 and 7 are connected in shuntacross the circuit and in series with a rheostat compris ing the contactarm 10, the fixed contacts 9 and the resistance 8. The position of thearm 10 is automatically controlled by means of the movable core 12, of acoil 13 connected in series with the lead 2 of the consumption circuit,and by a spring 14 connected to the arm 10 to move it against the pullof the core 12. I

The operation of the device is as follows: When the booster shoulddeliver a maximum current in one direction, the contact arm 10 assumesthe position shown in the drawing, in which all of the resistance 8 isin series with the coil 7 while there is no resistance in series withthe coil 6. The coil 6 is therefore producing its maximum efiect, andthe magneto-motive force produced by it is opposed only by a very slightmagneto-motive force due t6 thesmall current flowing through the coil 7and the resistance 8. As conditions on the circuit change and the arm 10is moved upward by the action of the coil 13, resistance is cut intocircuit with the coil 6 and out of circuit with the coil 7, so that asthe magneto-motive force produced by the coil 6 decreases, the opposingmagneto-motive force due to the coil 7 simultaneously increases. hen thearm 10 is midway of its travel, the resistance 8 is divided into twoequal portions, one in series with the coil 6 and the other in serieswith the coil 7, so that in this condition the coils exactlycounterbalance each other. hen the boost-er should generate a maximumcurrent flowing in the opposite direction, the arm 10 is moved to itsuppermost position, whereby the entire resistance 8 is put in serieswith the coil 6, and the coil 7 receives current across the system.

In a machine embodying my invention, it

' is not necessary that one coil be more powerful than the other, andthe resistance 8 can be made so high in proportion to the resistance ofthe coils that a coil with which the entire resistance is in series, ispractically eliminated from thelicld of the booster. If

an arrangclnentheretofore used were ad0pt ed, and the coil 6, forinstance, were always connected to produce a definite magnetomotiveforce in the field of the booster, the coil 7 would have to be largeenough to produce magneto-motive forces varying from zero to twice thatproduced by the coil 6 in order to obtain a range of regulationequal tothat obtained by the arrangement shown in the drawing. l urthermore, ina machine embodying my invention, a slight change in the position of theregulating arm 10 will produce a considerable change in the voltage andcurrent delivered by the booster, so that the regulator for the field ofthe booster can be made much smaller than would otherwise be the case.

My invention may be embodied in man other forms than that shown anddescribe and I therefore do not wish to be restricted to the exact formshown, but intend to cover by the appended claims all changes andmodifications within the spirit and scope of my invention.

WVhat I claim as new and desire to secure by Letters Patent of theUnited States, is:

1. In a. system of distribution, the combination with leads forming amain circuit, of a storage battery and a generator connected in seriesacross said circuit, equal and opposed differential shunt field coilsfor said generator, a resistance element connected in series with bothcoils, an arm movable over said resistance element to vary the amount ofresistance in circuit with each coil, and means responsive'to load insaid circuit for controlling said arm.

2. In a system of distribution, the com bination with a storage battery,a generator in series therewith, and differential field windings forsaid generator connected in parallel across at least one of said sourcesof current, of a resistance varying device comprising a resistance stripconnected between said windings, an arm movable over said resistance andconnected to complete a circuitthrough both said windings, and currentresponsive means for moving said arm to decrease the resistance betweensaid arm and one coil and simultaneously increase the resistance betweensaid arm and the other coil by equal amounts.

3. The combination of a system of distribution, a. storage batteryconnected there-- to, a generator in series with said battery, a sourceof current, differential field coils for said generator, each connectedat one endto one terminal of said source of cur rent and at the otherend to a resistance strip, an arm movable over said resistance strip toform a rheostat, said arm being connected to -the other terminal of thesource of current, and an electromagnet in series with said distributionsystem with its armature connected to said arm.

4. In a system of electrical distribution, the combination-with a mainsource of supply connected to leads which form a main circuit, of astorage battery and a generator connected in series across said maincircuit, differential field coils for the generator, each connected atone end to one of said leads, a. resistance strip connected between theother ends of said field coils, an arm movable over said strip andconnected to the other of said leads, and an electromagnetic devicecontrolled by the fluctuations of 15 the load on said main circuit andoperatively connected with said arm to move it over said strip. h

In Witness whereof, I have hereunto set my hand this 11th day ofSeptember, 1907. 20

JOHN C. BARRY. \Vitnesses:

BENJAMIN B. HULL,

MARGARET E. VOOLLEY.

